Formed in 1983 by Andrew Hewson, the company established itself as one of Europe's most successful 8-bit game publishers of the 1980s with classic hits such as PARADROID, QUAZATRON and URIDIUM. Much of this success can be attributed to Hewson owning his own cassette duplication facility, thus being able to respond to market trends much more quickly than most publishers who relied on larger companies to duplicate their software in set volumes. This allowed Hewson to produce low volume original product and thus support many independent developers which produced most of Hewson's games out-of-house.

Andrew Hewson proved quite adept at discovering unknown, talented developers (e.g Andrew Braybrook/Steve Turner aka Graftgold, Raffaele Cecco, John Phillips) and forged good working relationships with them. They developed the games and he marketed them, which allowed them a great deal of creative freedom that often paid handsome dividends in the playability of games produced. This worked well until the late 1980s when the games industry shed its cottage industry grassroots and became more commercialised. Consequently, the cost of developing games rose exponentially and developers required large cash advances from publishers to maximise the chances of games being completed and published. This spelt disaster for a lot of small independent publishers at the time and Hewson would be no exception in the longer term.

In 1987/88, Hewson entered the 16-bit market and converted two of their 8-bit smash hits, RANARAMA (Atari ST) and ZYNAPS (Amiga, Atari ST). Unfortunately, many of their early 8-bit ports didn't exploit the much-advanced 16-bit features of the Amiga and Atari ST, which translated into poor sales. Combined with diminishing returns from their budget Rack-It label in an increasingly saturated budget games market, Hewson ran into financial trouble in the late 1980s. This prompted a mass exodus from Hewson, which included its second in command (Debbie Silletoe to Telecomsoft), two in-house programmers (John Cumming and Dominic Robinson to Graftgold) and its most successful out-of-house development team in Graftgold (to Telecomsoft also). The loss of Graftgold was probably the most damaging given their phenomenal success with Hewson. However, Andrew Hewson only had himself to blame, having offered Graftgold neither a contract nor any cash advances to remain committed to the company. Hewson somehow managed to survive and legally challenged Telecomsoft's right to publish the two games (MAGNETRON, RAINBOW ISLANDS) that Graftgold had been developing before jumping ship. A court case followed, which delayed publication of the games and prompted Telecomsoft and Graftgold to settle out-of-court.

Unfortunately, few lessons were learnt in the late 80s transition to 16-bit machines. Hewson continued to churn out unremarkable 16-bit conversions of their 8-bit games, albeit charging Amiga and Atari ST owners full price for those that were only considered good enough for budget release originally on their 8-bit counterparts. In 1991, Hewson Associates closed its doors and was quickly succeeded by 21st Century Entertainment, with Andrew Hewson being one of its founding members.